1. Field of the Invention
The present invention relates to a hydraulic booster for operating a clutch releasing device or a braking system of a motor vehicle, and more particularly to a vibration damping mechanism for an input member of the booster.
2. Description of the Prior Art
In a conventional hydraulic booster for operating a clutch releasing device or a braking system of a motor vehicle, vibration of an input member occurs due to a self-excited vibration of a control valve mechanism and resonance of the control valve mechanism with a hydraulic pump pulsation generated under operating conditions of the booster thereby causing a disagreeable feeling or sensation to be communicated to the operator upon operation of the pedal.
In order to dampen such vibration of the input member, hydraulic damping means have been provided within the booster but the hydraulic damping means has failed, due to a simple construction and the small size thereof, to dampen a vibration of large magnitude of the input member which is generated where the control valve mechanism constitutes by a poppet valve mechanism provided between a power piston and the input member and an output member mechanically connected to a clutch releasing device.